organic chemistry 1 exam using lockdown browser
Last, First:______________________ CHEM 2321 Exam 1A 100_____________________ Organic Chemistry I 09/24/2019 Part I. Multiple Choice Questions 1-18. 5 pts. each (90 points) Answer these questions on a Scantron 882-E form in pencil. Write your NAME and Exam 1A on the scantron. 1. What is the chemical formula for Vitamin B2? a) C15H18N4O6 b) C15H20N4O6 c) C15H18N4O6 d) C17H20N4O6 e) C17H22N4O6 2. How many sp2 Oxygens are in B2? a) 0 b) 1 c) 2 d) 3 e) 4 3. There are ____ pi (π) bonds in the structure above (Vitamin B2)? a) 3 b) 4 c) 5 d) 6 e) 7 4. What best describes the overall dipole moment for the following molecule? F a. b. c. d. e. 0 D (no dipole) 5. What is the overall dipole moment that corresponds to the following molecule? O O a. b. c. d. e. 0 D – no dipole Questions 6-8. What are the geometries for the following bold and underlined atoms? a. linear d. trigonal pyramidal b. tetrahedral e. trigonal planar c. bent 6. CH3CO2H e. 7. H2O c. 8. H2CCCH2 a. Last, First:______________________ CHEM 2321 Exam 1A 100_____________________ Organic Chemistry I 09/24/2019 9. Which bond-line structure, as drawn, is identical to the given Newman projection? HH CH3F H CH3 a. F b. F c. F d. F 10. Which of the given resonance forms contributes most to the real structure of C6H4FO-1? a. O F b. O F c. O F d. O F e. both (b) and (d) 11. How many resonance forms of the cyclopentadienyl anion can be drawn, including the given structure? a. 2 d. 5 b. 3 e. 6 c. 4 12. Choose the most acidic acid a. d. b. e. c. 13. What is the value of Keq in the reaction below. O O+ + a) K = 1 b) K > 1 c) K < 1="" 14.="" which="" of="" the="" following="" best="" describes="" a="" lewis="" acid?="" a)="" a="" molecule="" that="" can="" accept="" a="" lone="" pair="" of="" electrons="" b)="" a="" molecule="" that="" can="" accept="" a="" lone="" pair="" of="" electrons="" c)="" a="" molecule="" that="" can="" donate="" a="" proton="" d)="" a="" molecule="" that="" can="" accept="" a="" proton="" 15.="" which="" of="" the="" following="" mechanisms="" is="" drawn="" most="" accurately="" (b:="Base," a-h="Acid)?" a)="" b:="" h="" a="" b="" ah+="" +="" b)="" b:="" h="" a="" b="" ah="" +="" +="" c)="" b:="" h="" a="" b="" ah="" +="" +="" d)="" b:="" h="" a="" b="" ah="" +="" +="" last,="" first:______________________="" chem="" 2321="" exam="" 1a="" 100_____________________="" organic="" chemistry="" i="" 09/24/2019="" 16.="" rank="" the="" labeled="" hydrogen="" atoms="" from="" the="" most="" acidic="" to="" least="" acidic="" proton.="" ha="" hb="" o="" hd="" o="" hc="" a.="" ha="">Hb>Hc>Hd d. Hb>Hc>Hd>Ha b. Hd>Hc>Hb>Ha e. Hc>Hd>Ha>Hb c. Hc>Hd>Hb>Ha 17-18. Select the proper name for the following two molecules. 17. a) 2-methyl-5-isopropylhexane b) 2-isopropyl-5-methylhexane c) 1,4-diisopropylbutane d) 2,3,6-trimethylheptane e) 2,5,6-trimethylheptane 18. a. 4-t-butyl -5-isopropyl-5-methyloctane b. 5-t-butyl-4-isopropyl-4-methyloctane c. 4-t-butyl-2,3-dimethyl-3-propylheptane d. 4-isopropyl-2,2,4-trimethyl-3-propyl heptane e. 4-isopropyl-5-methyl-4-t-butyloctane Last, First:______________________ CHEM 2321 Exam 1A 100_____________________ Organic Chemistry I 09/24/2019 Part II. Questions 19-20. (8 points each) Answer Questions 19 and 20 in the space provided on this exam. Clearly write your answer. Multiple answers will not be graded. For the following problems, show your work where possible. This allows me to award partial credit. I will not reconsider grades for answers written in pencil, but you are welcome to use any writing utensil that you wish. 19. a. Draw all resonance forms that describe the structure below (4 points): O NH2HO b. Which of the resonance forms (besides the one given) is most stable? Explain your answer briefly. (2 points) c. considering all of the resonance forms you’ve drawn for 19a., what partial charges (δ+ or δ-) would you expect to find on the molecule and where? Please draw your partial charges on the molecule, below. (2 points) O NH2HO Last, First:______________________ CHEM 2321 Exam 1A 100_____________________ Organic Chemistry I 09/24/2019 20. a. Draw the structure of 2,5-dimethylhexane in the space below. (2 points) b. Analyzing the C2-C3 of this molecule, draw I a Newman projection showing the highest potential energy conformational isomer, and II a Newman projection showing the lowest potential energy conformational isomer (6 points) I. II.